After a corporate event in Vienna, a colleague who had watched me perform said something that should have been a warning sign.
“Your card work is really smooth,” she said. “The way you handle the deck — it looks completely natural.”
I glowed. I stored that comment in the mental filing cabinet labeled “evidence that my practice is working.” It joined a growing collection: the audience member in Graz who said he had no idea how I did it. The event organizer in Salzburg who booked me for a second time. The friend who told me my ambitious card routine was the best magic he had ever seen in person.
Each piece of evidence confirmed what I believed: my practice methodology was sound, my progress was steady, and my performance level was rising.
What I did not store with equal care were the other signals. The table at the corporate event where one person was checking their phone during my close-up set. The moment in my mentalism piece where I could feel the audience’s attention waver. The fact that the colleague who praised my card handling said nothing about my patter, my presence, or the overall entertainment value of the performance. She praised the one thing I had been obsessively practicing. She was silent on everything else.
These signals existed. I perceived them in the moment. But they did not make it into the mental filing cabinet. They were filtered out, discarded, dismissed as noise. Because they did not confirm what I wanted to believe.
This is confirmation bias. And it may be the most dangerous cognitive bias a performer can have, because it does not just distort individual decisions. It distorts your entire understanding of where you are.
What Confirmation Bias Actually Does
Confirmation bias is the tendency to search for, interpret, and remember information in a way that confirms your existing beliefs, while ignoring or discounting information that contradicts them.
Note the three verbs: search, interpret, and remember. This is not a bias that operates at a single point. It operates at every stage of information processing.
At the search stage, confirmation bias determines what evidence you look for. If you believe your practice is working, you will naturally pay more attention to signs of improvement than to signs of stagnation. You will seek out feedback that validates your approach and avoid feedback that challenges it.
At the interpretation stage, confirmation bias determines how you process ambiguous information. A polite audience reaction can be interpreted as genuine appreciation (confirming your belief that the routine works) or as mere politeness (suggesting the routine needs improvement). Confirmation bias pushes the interpretation towards the confirming direction.
At the memory stage, confirmation bias determines what you remember. Positive feedback gets encoded strongly, replayed often, and stored permanently. Negative or neutral feedback gets encoded weakly, replayed rarely, and gradually forgotten.
The result is a distorted internal model of reality. You believe you know where you stand as a performer. You have evidence to support that belief. But the evidence has been curated by a process you are not aware of, and the curation consistently overstates your strengths and understates your weaknesses.
The Practice Session Feedback Loop
Confirmation bias is particularly insidious in practice because practice generates enormous amounts of ambiguous feedback, and ambiguous feedback is where the bias does its best work.
Consider a typical practice session. You run through a routine ten times. Three of those runs are excellent — the timing is perfect, the handling is smooth, the rhythm is right. Four are good — solid but not exceptional. Two are mediocre. One is rough.
How do you evaluate that session?
If confirmation bias is running the evaluation — and unless you have actively trained yourself to counteract it, it probably is — you focus on the three excellent runs. Those are the evidence that your practice is working. The four good runs are baseline — fine, expected, unremarkable. The two mediocre runs were just warm-up or fatigue. The one rough run was an aberration.
The session gets filed as “productive.” Your belief that you are improving is reinforced. And the pattern — three excellent out of ten — is accepted as progress rather than examined as a potential plateau.
But look at it without the bias. Three excellent runs out of ten means your consistency rate for peak performance is thirty percent. Seven out of ten runs were below your best level. If this pattern persists across sessions, it does not represent improvement. It represents a ceiling. You are hitting your peak occasionally and your average regularly, and the gap between the two is not closing.
Confirmation bias does not let you see this. It highlights the peaks, normalizes the average, and dismisses the valleys. The result is a performer who believes they are better than they are, because their self-assessment is based on their best moments rather than their typical ones.
The Audience Feedback Problem
Audience feedback is even more susceptible to confirmation bias than practice feedback, because audience feedback is almost entirely ambiguous.
What does applause mean? That the audience genuinely enjoyed the piece? That they are being polite? That they are responding to social pressure — everyone else is clapping, so they clap too? That they are relieved the piece is over and expressing that relief through the socially appropriate gesture?
Applause is consistent with all of these interpretations. Confirmation bias picks the one that confirms your existing belief and discards the rest.
I learned this the hard way when I started videotaping my performances and watching them with the sound off. Ken Weber’s advice about videotaping yourself was already transforming how I saw my own work, but watching with the sound off added another dimension. Without the audio — without hearing the applause, the laughter, my own voice filling the room — I was forced to read the audience’s body language.
What I saw was sobering. During moments I remembered as strong, some audience members were indeed engaged — leaning forward, eyes wide, body language open. But others were neutral. And in a few cases, people I had categorized in my memory as “engaged” were actually just… sitting there. Present but not transported. Watching but not experiencing.
My memory of those performances had been confirmation-biased. I remembered the engaged faces. I forgot the neutral ones. I remembered the strong reactions. I forgot the tepid ones. My internal highlight reel was made of the best moments, and I had been watching that highlight reel on repeat, convinced it represented the full picture.
It did not. The full picture was more complex, more mixed, and more honest than what I had been telling myself.
How Confirmation Bias Protects Bad Practice Habits
Here is where confirmation bias becomes genuinely dangerous for a performer’s development: it protects the very habits that are holding you back.
If you believe your practice methodology is effective, confirmation bias will find evidence to support that belief even when the methodology is clearly suboptimal. You will focus on the skills that are improving (which they will, because any practice produces some improvement) and ignore the skills that are stagnating (which your methodology may not be addressing at all).
I experienced this with my own practice structure. For a long time, I believed that my approach — warm up with familiar material, work on current routines, occasionally try new things — was sound. And I had evidence: my card handling was getting smoother. My timing on familiar routines was tightening. My comfort level on stage was increasing.
All of this was true. All of it was also irrelevant to the question of whether my practice was optimal. Card handling smoothness was improving because I was spending hours on it — any investment of time would produce some improvement. But was it improving at the rate it should have been given the time invested? Was it improving in the areas that mattered most for audience impact? Were there other skills — scripting, stage presence, audience management — that were stagnating because my practice did not address them?
Confirmation bias did not let me ask these questions. It showed me the smoothing card handling and said: see? It is working. The evidence was real. The conclusion was wrong. The bias had selected the evidence that supported its preferred narrative and hidden the evidence that would have challenged it.
It was not until I started the practice methodology research — studying how elite performers across disciplines actually structure their training — that the bias cracked. Because the research provided an external framework for evaluating my practice, one that was not subject to my own confirmation bias. The research did not care what I believed about my practice. It simply showed what effective practice looked like, and the gap between that picture and my actual habits was too large to dismiss.
The Disconfirmation Experiment
In science, the standard methodology for testing a hypothesis involves trying to disprove it, not prove it. You design experiments that would produce specific results if the hypothesis is wrong. If the experiments fail to disprove the hypothesis, confidence in it increases. But the starting posture is skepticism, not belief.
This is the opposite of how most performers evaluate their own practice and performance. We start from belief — “my practice is working,” “my show is strong,” “my material is good” — and then look for evidence to support that belief. We are running confirmation experiments, not disconfirmation experiments.
I have adopted a disconfirmation practice in my own self-evaluation. Instead of asking “what evidence suggests my practice is working?” I ask “what evidence would I expect to see if my practice were not working?”
The answers are uncomfortable but illuminating.
If my practice were not working, I would expect to see: a consistency rate that is not improving over time, even if the peaks are high. Audience reactions that are pleasant but not intense. Skills that plateau after an initial learning curve. A repertoire that has not meaningfully evolved in the past six months.
When I look for these specific signals — actively search for disconfirming evidence rather than passively accumulating confirming evidence — the picture that emerges is less flattering but far more useful. I can see where I am actually stagnating. I can see where my assessment of my own skill level has been inflated by selective attention. I can see the gaps that confirmation bias has been papering over.
The Video Counter-Measure
The single most effective tool I have found for counteracting confirmation bias in performance is video review with a specific protocol.
The protocol is simple. I watch a recording of a performance three times.
The first viewing is unstructured. I watch it however I naturally watch it, and I note what catches my attention. This viewing is almost entirely confirmation-biased. I notice the strong moments. I feel good about them. I notice the weak moments but quickly move past them.
The second viewing is focused exclusively on the audience. I ignore myself entirely and watch only the audience’s reactions. Not the reactions I remember. The reactions that actually occurred. I watch for neutral faces during moments I thought were strong. I watch for engagement during moments I thought were weak. I watch for the moments where attention drifts, where body language closes, where the energy in the room shifts.
The third viewing is the disconfirmation viewing. I watch specifically looking for evidence that the performance was weaker than I believe it to be. This is the hardest viewing because it requires actively fighting the bias. Every instinct wants to find the strong moments. The protocol demands that I find the weak ones.
Three viewings. Three different lenses. Three increasingly honest pictures of the same performance. The gap between the first viewing and the third is always significant, and that gap is a direct measure of how much confirmation bias was distorting my self-assessment.
Beyond Performance: Confirmation Bias in Learning
Confirmation bias does not only affect how you evaluate your performances. It affects how you learn.
When I read a magic book or watch a tutorial, confirmation bias shapes what I absorb. Information that aligns with what I already believe about performance and practice gets absorbed readily. Information that challenges my existing beliefs gets filtered, dismissed, or reinterpreted to fit.
I noticed this pattern when I re-read Ken Weber’s “Maximum Entertainment” for the second time. The first reading had been revelatory — I discovered concepts that changed how I thought about performing. But when I re-read it a year later, I was struck by passages I had completely overlooked the first time. Passages that challenged habits I had developed. Passages that contradicted approaches I had adopted.
I had not missed those passages because they were hidden. I had missed them because they did not confirm what I believed at the time. My brain had filtered them as irrelevant. On the second reading, with a year more experience and a growing awareness of my own biases, the filter was weaker, and the challenging material got through.
This is why I now make a practice of revisiting key books and resources regularly. Not because the content has changed, but because my biases may have filtered different things on different readings. Each re-reading is an opportunity for disconfirming evidence to slip past the filter.
The Honest Mirror
I want to end with the most uncomfortable truth about confirmation bias: you cannot fully overcome it. The bias is built into the architecture of human cognition. It operates below conscious awareness. It is faster than your deliberate thinking, more persistent than your good intentions, and more creative than your countermeasures.
What you can do is build systems that partially compensate for it. The video review protocol. The disconfirmation questions. The practice of seeking out feedback from people who have no incentive to flatter you. The discipline of re-reading material that challenged you rather than material that confirmed you.
None of these systems are perfect. All of them are better than nothing.
And the first step — the one that makes all the other steps possible — is admitting that your internal model of your own skill level is almost certainly wrong. Not slightly wrong. Systematically wrong, in a specific direction: biased towards overestimation, biased towards highlighting strengths and hiding weaknesses, biased towards confirming that whatever you are currently doing is working.
That admission is painful. It was painful for me. After years of accumulating a mental filing cabinet full of positive feedback and encouraging signs, the realization that the filing system was rigged felt like discovering that the foundation of my confidence was built on edited footage rather than raw reality.
But edited footage, however flattering, does not make you better. Raw reality does. And the willingness to watch the raw footage — to seek out the disconfirming evidence, to look for the neutral faces in the audience, to honestly assess the gap between where you think you are and where you actually are — is the beginning of genuine improvement.
The confirmation bias will not go away. But it can be caught in the act. And every time you catch it, the picture gets a little clearer, a little more honest, and a little more useful for deciding what to work on next.